Air Pollution Chapter 18

Core Case Study: South Asia’s Massive Brown Cloud Asian Brown Cloud Causes Chemical composition Areas impacted Air pollution connects the world Steps taken in China and India to reduce air pollution

The Asian Brown Cloud

Air Pollution in Shanghai, China, in 2004

18-1 What Is the Nature of the Atmosphere? Concept 18-1 The atmosphere is structured in layers, including the troposphere, which supports life, and the stratosphere, which contains the protective ozone layer.

The Atmosphere Consists of Several Layers Atmosphere varies in Density Atmospheric pressure

Air Movements in the Troposphere Play a Key Role in Earth’s Weather and Climate 75–80% of the earth’s air mass Closet to the earth's surface Chemical composition of air Rising and falling air currents: weather and climate Involved in chemical cycling

The Stratosphere Is Our Global Sunscreen Similar composition to the troposphere, with 2 exceptions Much less water O3, ozone layer, filters UV Location

Natural Capital: The Earth’s Atmosphere Is a Dynamic System with Four Layers

18-2 What Are the Major Outdoor Pollution Problems? Concept 18-2 Pollutants mix in the air to form industrial smog, mostly the result of burning coal, and photochemical smog, caused by motor vehicle, industrial, and power plant emissions.

Air Pollution Comes from Natural and Human Sources (1) Natural sources Dust blown by wind Pollutants from wildfires and volcanoes Volatile organics released by plants Withdrawing groundwater

Air Pollution Comes from Natural and Human Sources (2) Human sources: mostly in industrialized and/or urban areas Stationary sources Mobile sources

Case Study: Air Pollution in the Past: The Bad Old Days (1) Discovery of fire Middle Ages Industrial Revolution London, England 1850s 1952: yellow fog Clean Air Act of 1956

Case Study: Air Pollution in the Past: The Bad Old Days (2) United States 1948: Donora, PA; first U.S. air pollution disaster 1963: New York City Global problem

Some Pollutants in the Atmosphere Combine to Form Other Pollutants Primary pollutants Secondary pollutants Air quality improving in developed countries Much more needs to be done in developing countries Indoor pollution: big threat to the poor

Sources and Types of Air Pollutants

Indoor Air Pollution

What Are the Major Outdoor Air Pollutants? (1) Carbon oxides Carbon monoxide (CO) Carbon dioxide (CO2) Sources Human health and environmental impact

What Are the Major Outdoor Air Pollutants? (2) Nitrogen oxides (NO) and nitric acid (HNO3) Sources Acid deposition Photochemical smog Human health and environmental impact Sulfur dioxide (SO2) and sulfuric acid (H2SO4)

What Are the Major Outdoor Air Pollutants? (3) Particulates Suspended particulate matter (SPM) Fine Ultrafine Sources Human health and environmental impact

What Are the Major Outdoor Air Pollutants? (4) Ozone (O3) Sources Human and environmental impact Volatile organic compounds (VOCs) Hydrocarbons and terpenes

Chemical Reactions That Form Major Outdoor Air Pollutants

Stepped Art Table 18-1, p. 473

Statue Corroded by Acid Deposition and Other Forms of Air Pollution, RI, U.S.

Science Focus: Detecting Air Pollutants Chemical instruments Satellites Nanotechnology Biological indicators Lichens

Natural Capital: Lichen Species, Vulnerability to Air Pollutants

Case Study: Lead Is a Highly Toxic Pollutant (1) Does not break down in the environment Sources Human health and environmental impact Most vulnerable

Case Study: Lead Is a Highly Toxic Pollutant (2) Reduction of lead (Pb) Unleaded gasoline Unleaded paint Still problems 2007: toys with Pb paint recalled Global ban on lead in gasoline and paint

Solutions: Lead Poisoning, Prevention and Control

Burning Coal Produces Industrial Smog Chemical composition of industrial smog Reduction of this smog in urban cities of the United States China and smog Human deaths

How Pollutants Are Formed from Burning Coal and Oil, Leading to Industrial Smog

Sunlight Plus Cars Equals Photochemical Smog Chemical composition Sources VOCs + NO2 + Heat + Sunlight yields Ground level O3 and other photochemical oxidants Aldehydes Other secondary pollutants Human health and environmental impact

A Model of How Pollutants That Make Up Photochemicals Are Formed

Global Outlook: Photochemical Smog in Santiago, Chile

Several Factors Can Decrease or Increase Outdoor Air Pollution (1) Outdoor air pollution may be decreased by Settling of particles due to gravity Rain and snow Salty sea spray from the ocean Winds Chemical reactions

Several Factors Can Decrease or Increase Outdoor Air Pollution (2) Outdoor air pollution may be increased by Urban buildings Hills and mountains High temperatures Emissions of VOCs from certain trees and plants Grasshopper effect Temperature inversions

A Temperature Inversion

18-3 What Is Acid Deposition and Why Is It a Problem? Concept 18-3 Acid deposition is caused mainly by coal-burning power plant and motor vehicle emissions, and in some regions, threatens human health, aquatic life and ecosystems, forests, and human-built structures.

Acid Disposition Is a Serious Regional Air Pollution Problem Acid deposition, acid rain Formation Local versus regional problems Effects of prevailing winds Buffers Where is the worst acid deposition?

Natural Capital Degradation: Acid Deposition, Acid Rain

Current and Possible Future Acid Rain Problem Areas

Acid Deposition Has a Number of Harmful Effects (1) Human respiratory disorders Aquatic ecosystems affected Release of toxic metals

Acid Deposition Has a Number of Harmful Effects (2) Leaching of soil nutrients Loss of crops and trees Damage to buildings, statues, and monuments

Natural Capital Degradation: Air Pollution Damage to Trees in North Carolina, U.S.

Science Focus: Revisiting Hubbard Brook to Study Effects of Acid Rain White Mountains, NH, U.S. Experimentation supports: Trees do not suffer from direct contact with acid rain Nutrients are leached out of the soil Effect of Ca2+ on regrowth of the forest

We Know How to Reduce Acid Deposition Prevention approaches Clean up Add lime to neutralize acidified lakes and soil Add phosphate fertilizer to neutralize acidified lakes

Solutions: Acid Deposition, Prevention and Cleanup

18-4 What Are the Major Indoor Air Pollution Problems? Concept 18-4 The most threatening indoor air pollutants are smoke and soot from wood and coal cooking fires (a hazard found mostly in developing countries) and chemicals used in building materials and products.

Indoor Air Pollution Is a Serious Problem (1) Developing countries Indoor burning Poor suffer the greatest risk Developed countries Indoor air pollution is greater than outdoor air pollution

Indoor Air Pollution Is a Serious Problem (2) Why? 11 of the common air pollutants higher inside than outside Greater in vehicles than outside Health risks magnified: people spend 70–98% of their time is indoors

Indoor Air Pollution Is a Serious Problem (3) Who are at greatest risk from indoor air pollution? Children under 5 and the elderly Sick Pregnant women People with respiratory disorders or heart problems Smokers Factory workers

Indoor Air Pollution Is a Serious Problem (4) Four most dangerous indoor air pollutants Tobacco smoke Formaldehyde Radioactive radon-222 gas Very small particles Sources of these pollutants Human health risks

Indoor Air Pollution Is a Serious Problem (5) Other possible indoor air pollutants Pesticide residue Pb particles Living organisms and their excrements E.g., Dust mites and cockroach droppings Airborne spores of molds and mildews Sick-building syndrome

Some Important Indoor Air Pollutants

Science: Magnified View of a Household Dust Mite in a Dust Ball

Case Study: Radioactive Radon Gas Sources Human health risks Testing for radon Correcting a radon problem

Science: Sources and Paths of Entry for Indoor Radon-222 Gas

18-5 What Are the Health Effects of Air Pollution? Concept 18-5 Air pollution can contribute to asthma, chronic bronchitis, emphysema, lung cancer, heart attack, and stroke.

Your Body’s Natural Defenses against Air Pollution Can Be Overwhelmed Respiratory system protection from air pollutants Role of cilia, mucus, sneezing, and coughing Effect of smoking and prolonged air pollution exposure Chronic bronchitis Emphysema

Major Components of the Human Respiratory System

Normal Human Lungs and the Lungs of a Person Who Died of Emphysema

Air Pollution Is a Big Killer 3 Million deaths per year world-wide Mostly in Asia Main causes EPA: proposed stricter emission standards for diesel-powered vehicles Link between international trade and air pollution Cargo ships and pollution

Premature Deaths from Air Pollution in the U.S.

18-6 How Should We Deal with Air Pollution? Concept 18-6 Legal, economic, and technological tools can help to clean up air pollution, but much greater emphasis should be focused on preventing air pollution.

Laws and Regulations Can Reduce Outdoor Air Pollution (1) United States Clean Air Acts: 1970, 1977, and 1990 EPA National ambient air quality standards (NAAQs) for 6 outdoor criteria pollutants National emission standards for 188 hazardous air pollutants (HAPs) Toxic Release Inventory (TRI)

Laws and Regulations Can Reduce Outdoor Air Pollution (2) Good news in U.S. Decrease in emissions Use of low-sulfur diesel fuel Cuts pollution Developing countries More air pollution

Case Study: U.S. Air Pollution Can Be Improved (1) Rely on cleanup more than prevention of pollution Raise fuel-efficiency for cars, SUVs, and light trucks Better regulation of emissions of motorcycles and two-cycle gasoline engines Regulate air pollution for oceangoing ships in American ports

Case Study: U.S. Air Pollution Can Be Improved (2) Why are airports exempt from many regulations? Regulate greenhouse gas emissions Ultrafine particles are not regulated Urban O3 levels too high

Case Study: U.S. Air Pollution Can Be Improved (3) What about indoor air pollution? Better enforcement of the Clean Air Acts Is intense pressure needed from citizens to make improvements?

We Can Use the Marketplace to Reduce Outdoor Air Pollution Emission trading or cap-and-trade program Mixed reactions to program SO2 emissions down significantly NO2 will be tried in the future

There Are Many Ways to Reduce Outdoor Air Pollution 1980 –2006 SO2 emissions from U.S. electric power plants decreased by 66% NOx emissions by 41% Particulate emissions by 28% Older plants not governed by the same regulations New cars have better emissions

Solutions: Stationary Source Air Pollution

Solutions: Motor Vehicle Air Pollution, Prevention and Cleanup

Reducing Indoor Air Pollution Should Be a Priority Greater threat to human health than outdoor pollution What can be done? Prevention Cleanup

Solutions: Indoor Pollution, Prevention and Cleanup or Dilution

What Can You Do? Indoor Pollution: Ways to Reduce Your Exposure

We Need to Put More Emphasis on Pollution Prevention Output approaches New shift to preventing outdoor and indoor pollution Pressure from citizens

Solutions: Air Pollution, Ways to Prevent It Over the Next 30–40 Years